Redirect To Standard New Note & New Attachment Pages Using Apex

Redirect to New Attachment:

public PageReference redirectToNewAttachment() {
   PageReference pgRef = new pageReference('/p/attach/NoteAttach?pid=' + String.valueof(acc.Id).subString(0, 15) + '&retURL=' + acc.Id);
   pgRef.setRedirect(true);
   return pgRef;
}

Redirect to New Note:

public PageReference redirectToNewNote() {
   PageReference pgRef = new pageReference('/002/e?parent_id=' + String.valueof(acc.Id).subString(0, 15) + '&retURL=' + acc.Id);
   pgRef.setRedirect(true);
   return pgRef;
}